User's Manual

GE865 Hardware User Guide
1vv0300799 Rev.11 – 13-07-2010
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 26 of 82
5.3 Resetting the GE865
5.3.1 Hardware Unconditional restart
WARNING:
The hardware unconditional Restart must not be used during normal operation of the
device since it does not detach the device from the network. It shall be kept as an
emergency exit procedure to be done in the rare case that the device gets stacked
waiting for some network or SIM responses.
To unconditionally reboot the GE865, the pad RESET# must be tied low for at least 200 milliseconds
and then released.
The maximum current that can be drained from the RESET# pad is 0,15 mA.
NOTE:
Do not use any pull up resistor on the RESET* line nor any totem pole digital output.
Using pull up resistor may bring to latch up problems on the GE865 power regulator
and improper functioning of the module. The line RESET* must be connected only in
open collector configuration.
TIP:
The unconditional hardware restart must always be implemented on the boards and
the software must use it as an emergency exit procedure.
A simple circuit to do it is: